Grinding apparatus



Feb. 21, 1933.

F. G. MUSHENO GRINDING APPARATUS Filed Aug. 27, 1931 INVENTOR PatentedFeb. 21, 1933 UNITED STATES PATENT OFFICE FRED G. IU'SHENO, OISCHUYLKHIL -HAVEN, PENNSYLVANIA, ASSIGNOB TO ALLEGHENY STEEL COMPANY ACORPORATION OF PENNSYLVANIA same manure Application filed August 27,1981.

This invention relates to the grinding grind and/or polish'the interiorsur aces of.

cylinders, tubes and the like.

Since the development of the art relating to the manufacture of seamlesstubing, pipe, cylinders and the like, industry hasfound many and variedapplications for their use. Some applications require that the interiorsurface of such tubin cylinders, pipe and the like be smooth anpolished.

Usually the tubing, cylinders, pipe and the like referred to above aremade 1n relatively long lengths; therefore the smoothing, grindingand/or polishing of the interlor surfaces thereof present a difficultproblem because special grinders are required. Grinders for this classof work require holders for the abrasive elements or stones, soconstructed thatthe grinding and polishing operations may be worked outeffectively and quickly.

An object of this invention is to provide an internal grinder for theaforesaid pur-. pose that shall be simple in construction and efficientin operation.

Another object of the invention is to provide for supporting abrasiveelements, such as grinding stones, within pipe, tubing, cylinders andthe like and yieldmgly urging the elements or stones into engagementwith the surfaces to be ground and/or polished. The invention comprisesthe details of construction and the arrangement and combination of partsas will be more fully set,

forth in detail.

Other objects of the invention will, in part, be apparent, and will, inpart, be obvious from the following description taken in conjunctionwith the accompanying drawing in which Figure 1 is a view in perspectiveof an assembled grinder arranged and constructed in accordance with anembodiment of the invention; I

Fig. 2 is a view in perspective-of a holder for abrasive elements orstones embodied in '50 the arrangement shown in Fig. 1;

Serial No. 559,623.

sive element or stone;

Fig. 4 is a view of a shaft or mandrel embodied in the structure shownin Fig. 1;

Fig. 5 is a diagrammatic illustration of 5 apparatus for driving'thegrinder and moving the pipe, cylinder or the like, over the grinder inthe process of grinding and/or polishing the bore or the internalsurface of the same.

Throughout the drawing and the specification like reference charactersindicate like parts.

Referring to the drawing, an internal grinder 1 is illustrated which isadapted to e rotatably disposed within the bore of a cylinder, tube orpipe 2. The pipe may be supported on a carriage or conveyor 3 arrangedfor reciprocating travel. The carriage 3 includes collars or clamps 4mounted on standards 5 carried by the carriage for holding the pipe,tube or cylinder 2 in such position that its longitudinal axis is inalinement and coincides with the axis of rotationv of the grinder 1.

While the ipe is shown as being movable and the grin er stationary, itwill be appreciated that the pipe may be held stationary and the grinderinoved longitudinally therein. 80

The carriage 3 may be driven by a motor (not shown), suitable control(not shown) being emplo ed to reverse the motor at predeterminedmtervals, thereby to reverse the direction of movement of the carriageat predetermined intervals or when it has traveled a predetermineddistance in one direction or the other.

The grinder comprises a shaft or mandrel 6 on which a holder 7forabrasive elements or grinding stones 8 is secured. The holder isillustrated more clearly in Fig. '2 and comprises a cylinder having aplurality of pockets or recesses 9 disposed parallel to the axis of thecylinder and, also, to the axis of rotation of shaft 6. The holder 7 maybe secured to the shaft 6 by means of a set screw 10. As illustratedthepockets or recesses 9 are substantially, rectangular in transversesection and spaced approximately Fig. 3 is a view in perspective of anabraninety degrees apart, however, the shape and number of recesses orpockets employed and the angular spacing thereof may vary asrequirements dictate.

The abrasive elements or stones 8 are 11- lustrated more particularly inFig. 3. As there illustrated, each stone or abrasive element -8 isrelatively long as compared to the depth of the pockets or recesses 9and may be substantially rectangular in transverse section. The stonesare preferably of such size that they may move freely mto and out of thepockets or recesses 9.

In order that the stones or abrasive elements 8 may be yieldingly urgedoutwardly of the pockets or recesses 9 and into engagement with theinternal surface of the pipe, tube or cylinder 2, a plurality of springs11 are provided. As shown the spr ngs comprise relatively long strips ofspring metal and extend through the pockets or recesses 9 in the holder7.

As illustrated in Figs. 1 and 5, the springs are so positioned that thecentral portions thereof are within the pockets of the holder 7. Thesprings may be bowed upwardly from the opposite ends thereof towardsthelr middle portions. By so bowing the spr ngs, the abrasive elementsor stones will yieldingly engage the internal surface of the ipe orcylinder 2 at all times as the gun mg stones or elements are worn away.

The tension of the springs may be so adjusted that the pressure at whichthe grinding stones or elements bear upon the surface of the pipe ortube being ground, W111 be of that value conducive to efiicient, qualitygrinding and/or polishing. The rate of grinding or cutting away of thesurface metal may be regulated by the speed of rotation of the mandrelshaft 6 and by the type of abrasive element or stone selected. Likewisethe quality or character of the polished surface desired may becontrolled by choos ing the proper type of grinding element or stone. Itis to be understood that other factors enter into the rate of grindingand the quality of surface polish and these factors are generally knownto those skilled in this particular art.

As shown in Figs. 1 and 5, the left hand ends of springs 11, as seen inthe drawing, are secured to a collar or cylinder 12 which a is held fastto the shaft 6 by means of a set screw 13. The opposite ends of thesprings are secured to a collar or cylinder 14 which is movablelongitudinally of shaft 6 as the springs 11 expand or contract. In orderto move rather freely along the shaft 6 as the springs 11 expand orcontract.

Inorder that the rinder 1 may be held or supported central y within thetube or pipe 2, bearing members 16 of suitable bearmgmaterial areprovided. The bearing members 16 may be mounted adjacent to collars 12and 14, asshown more particularly in Fi 1 and 5. It is preferred tomount the gearing members 16 loosely on theshaft 6 so that they may turnthereon and also permit the tube or cylinder to slide freely thereover.

In order to limit the longitudinal movement of bearing member 16adjacent to col lar 12, a collar 17 is mounted on the shaft and securedthereto by a set screw 17' or other suitable means. Bearing member 16may, therefore, move between collars 12 and 17. In order to limit thelongitudinal movement of bearing 16 adjacent to collar 14, collars 18are mounted on the shaft 6 at opposite ends of the bea 'ng, the collarsbeing secured to the shaft b set screws 19, or

other suitable means.

In operation, a tube, pipe or cylinder is mounted fast in the'collars orclamps 4 of the carriage and the grinder inserted into the bore to beground. One end of the grinder mandrel 6 is coupled to a driven shaft 21by a coupler 22. Shaft 21 is journaled in pedestal bearings 23.

In order that the grinder may be driven at the proper speed, a motor 24,coupled to shaft 21 by pulley 25, belt 26 and pulley 27, is provided.

When the grinder and tube or cylinder have been set up, as shown in Fig.5, the motor 24 is started and adjusted to the desired speed. Thegrinder will, therefore, be driven at the speed required for the type ofgrinding to be carried out. As the grinder rotates, carriage 3 is drivenreciprocatingly thereby reciprocating the pipe longitudinall of thegrinder.

T e grinder may be lubricated in any manner desired so 'long assufiicient fluid is supplied to the surfaces being ground.

When grinder 1 is rotating within the pipe, tube or cylinder 2, thesprings and the centrifugal forces acting on the stones or abrasiveelements 8 tend to force them outwardly against the surface being groundand/or polished; Also the centrifugal forces acting on springs 11, tendto hold the springs firmly against the stones, thereby preventingchattering of the stones and springs. The springs in conjunction withmovable collar 14 automatically vary the 'force exerted on the abrasiveelements while the machine is in operation, in accordance with thecontour of the surface being ground and the speed of rotation of themandrel 6.

While only a single embodiment of the invention has been described .andillustrated,

it is to be understood that several and various modifications andchangesmay be made in the grinder without depart from the spirit andscope of the mvent on. It is desired, therefore, that only suchlimitations shall be placed on the invention as are 1mposed by the priorart and the appended claims.

What I claim as new and desire to secure by Letters Patent is:--

1. An internal grinder comprising a shaft a holder for abrasive elementsfixed to said shaft, abrasive elements disposed in said holder, meansyieldingly urging said. elements outwardly of the holder, and meansmovable along the shaft adapted to automatically vary the force exertedby said yielding means on the abrasive elements in the operation of saidgrinder.

2. An internal grinder comprisin a shaft, a holder for abrasive elementsfixe to said shaft, abrasive elements disposed in said holder, meansyieldingly urging said elements outwardl of the holder and bearingmembers on sai shaft disposed at each side of the holder for supportingthe grinder centrally within the bore of a tube, cylinder or the like.

3. An internal grinder comptrising a shaft, a holder fixed to said shaan havin pockets therein concentricall dispose thereabout, leaf springsextending through said pockets, means rigidly securing said sp at oneend to the shaft, means mova ly securing said sprin s at the other tosaid shaft and abrasive e ements in said pockets and bearing on saidsprings.

4. An internal grinder comarising a shaft, a holder fixed to said sha anhavin pockets therein concentricall dispose thereabout, leaf springsextending through said pockets, means rigidly securing sald s rings atone end to the shaft, means mova l securin said springs at the other tosai shaft, a rasive elements'in said gmkets and bearing on said springsand a members mounted on the shaft adjacent spring-securing means.

5. internal grinder comprisin a shaft, a holder fixed to said shaft anhaving pockets therein concentrically disposed thereabout, a collarrigidly. secured to said shaft on one sideof the holder, a collarmovably mounted on said shaft on the other side of said holder, leafsprings extendin through said pockets, the ends of sai s rin beingsecured to said collars and a rasive elements in said pockets andhearing on said springs.

6. An-internal grinder comprising a shaft, a holder fixed to said shaftand having ckets therein concentrically disposed t ereabout, a collarrigidly secured to said shaft to one side of the holder, a collarmovably mounted on said shaft on the other side of holder, leaf springsextending through said pockets, the ends of said springs being securedto said collars, abrasive elements in said pockets and bearing on said srings and bearing members on said shaft a jacent to the outer ends ofsaid collars for supporting the grinder centrally within the bore of atube, cylinder or the like.

7. An internal grinder comprising a shaft, a holder fixed to said shaftand having 001:- ets therein concentrically disposed t ereabout, acollar rigidly secured to said shaft to one side of the holder, a collarmovably mounted on said shaft on the other side of said holder,resilient strips extending throu h said pockets, said strips being bowoutwardly at'the pockets, the ends of said strips being secured to saidcollars, and

.abrasive elements mounted in said pockets and bearing upon said strips.

8. An internal grinder comprising a shaft, a holder fixed to said shaftand havmg ockets therein concentrically disposed t ereabout, a collarrigidly secured to said shaft to one side of the holder, a collarmovably mounted, on said shaft on the other side of said holder,resilient strips extending, through said pockets, said strips being boweoutwardly at the pockets, the ends of said strips being secured to saidcollars, abrasive elements mounted in said ockets and bearing upon saidstrips and aring members on said shaft adjacent to the outer ends ofsaid collars for supporting the grinder centrall within the bore of atube, cylinder or the ike.

9. An internal grinder comlprising a shaft,

a holder on said shaft and aving at least one guideway therein, a membersecured to the. shaft at one end of the holder, a member movably mountedon said shaft at the other end of the holder, a resilient stripextending through said guideway and having its 0 pcsite ends secured tosaid members, an an abrasive element mounted in said guideway andbearing on said strip.

10. An mternal grinder comprising a shaft, a holder on said shaft andhaving at least one guideway therein, a member secured to the shaft atone end of the holder, a member movably mounted on said shaft at theother end of the holder, a resilient strip extending through saidguideway, said strip being secured to said members, and an abrasiveelement mounted in said guideway and bearin on said strip.

11. An internal I grinder comprising a shaft, a holder on said shaft,said holder having at least one guideway therein disposed longitudinallyof and opening radially outward with respect to the axis of rotation ofthe shaft, a member secured to the shaft at one end of the holder, amember movably mounted on said shaft at the other end of the holder, aresilient strip extending through said guideway and having its oppositeends secured to said members, and an abrasive element mounted in saidguideway and bearing on said stri In testimony whereo I have hereuntosubscribed my name this 21st day of August,

FRED G. MUSHENO.

